Geology and paleontology have a lot in common: they complement each other, they concern themselves with vast expanses of time, and they're both relatively new disciplines. Geology not only helps us study the history of life on earth, it enables us to comprehend events beyond our control, such as earthquakes and volcanoes. Oddly enough, continental drift, the mechanism causing earthquakes and volcanoes, was not widely understood until the 1960s, even though Alfred Wegener described the process in 1912, and Abraham Ortelius suggested the possibility in the 16th century.

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Now appears in:Rocks and Fossils by Busbey, Coenraads, Willis and Roots
Ever seen an ancient Chinese seismometer? That's what this is. Each tremor causes a ball to drop from the griffin's mouth into the frog's. Not exactly the accuracy of the USGS, but not a bad idea, either. Frequent, deadly earthquakes caused the Chinese to try detecting seismic activity starting in the second century AD.

Century: 16thScientist/artist: Marcantonio RaimondiName:Witches' Sabbath with Reconstructed Skeleton of MonsterNow appears in:Fossils: Evidence of Vanished Worlds by Yvette Gayrard-Valy
Europeans frequently portrayed fossilized creatures as instruments of the devil, along with goats, potions and witches. Fossils were said to have been "begotten by Satan to vie with God," a charge some biblical literalists still level today.

Year: 1893Author: Orlando FergusonOriginally published as: "Map of the square and stationary earth: four hundred passages in the Bible that condemn the Globe Theory, or the Flying Earth, and none sustain it; this map is the Bible map of the world"Now appears in: "The Age of Disbelief" by Joel Achenbach in National Geographic and Library of Congress (http://www.loc.gov/item/2011594831)
Christopher Columbus knew better than to fear sailing off the edge of the earth, though the worry was somewhat understandable in the 15th century. But 400 years later, South Dakota businessman Orlando Ferguson remained unpersuaded by centuries of circumnavigation of the globe, including the ocean voyages one suspects carried his own ancestors from the Old World to the New. All the evidence he needed came from his Bible. In this map, Ferguson has stationed angels at each of the earth's four corners. Off to the right, Ferguson tries to show the implausibility of heliocentrism, showing desperate men flapping from a speeding planet. North and South America — little discussed in the Bible he cites as evidence — nevertheless appear in the middle of Ferguson's map.Larger image available

Year: 1485Scientist: Barthélemy de GlanvilleOriginally published in:Le Livre des Propriétés des ChosesNow appears in:The Discovery of the Past by Alain Schnapp
An old saying in academic circles is: "Language affects perception." A good example is how differently the term "fossil" has been defined. Today, a fossil is defined as any evidence of ancient life, but centuries ago, a fossil was anything dug out of the ground, and that could be a crystal or a human artifact. No wonder scholars took so long to figure out what fossils really were. Evidence of this old confusion appears in this 15th-century woodcut. This prolific hillside gives rise both to vases and animals, all of them emerging from gaps in the ground.Larger image available

Year: 1512Scientist: Jacques d'Etaples LefèvreOriginally published in:Meteorologia AristotelisNow appears in: "Being the World Eternal" by Ivano Dal Prete in Isis
Today we associate "meteorology" with the study of the atmosphere and weather, but during the Renaissance, the term had a broader definition, including the combination of elements (earth, air, water and fire). This woodcut shows the elemental interactions studied by 15th- and 16th-century meteorologists. Works such as these contained plenty errors, but they also included something we don't often attribute to medieval and Renaissance Europeans: acceptance of an ancient earth. Meteorological works such as this frequently discussed the planet's long history. In this book, Lefèvre mentioned the Noachian flood only to say that it "does not pertain to nature, but to divine revenge." He was in plenty of good company. In 1542, Fausto da Longiano rejected the universality of Noah's flood and endorsed a 36,000-year cycle accepted by many other scholars at the time. Nearly two centuries earlier, Jean Buridan of the University of Paris had already rejected that same 36,000-year cycle as too short. In other words, the biblically literal creation date of 4004 BC publicized by James Ussher and still influential among many creationists today was largely born in the 17th century. Embroiled in the Reformation and Counter-Reformation, religious authorities and scholars came to believe that taking the Bible seriously meant taking it literally. Yet about the same time biblical literalism was taking hold, it was also being undermined. Niels Stensen (Steno) discovered that rocks are deposited in layers with older rocks underneath newer ones. Over the next couple centuries, the oddness of the fossils found in older rocks (and the dearth of human remains found in those layers) enabled savants and geologists to piece together an ancient history for our planet, overturning the young-earth literalism of the 17th century.Larger image available

Year: 1708Scientist:Johann Jakob ScheuchzerOriginally published in:Bildnissen verschiedener Fischen und dero Theilen, welche in der Sündfluth zu Grund gegangenNow appears in:Cultures of Natural History edited by Jardine, Secord and Spary
This engraving of a fossil fish was beautifully detailed and probably accurate. What missed the mark was Scheuchzer's characterization of this and other fish fossils as "The Different Fish that Died in the Great Flood."Expanded image available

Year: 1706Scientist: Levinus VincentOriginally published in:Wondertooneel der NatureNow appears in:Redressing the Balance: Levinus Vincent's Wonder Theatre of Nature by Bert van de Roemer in Public Domain Review
Cabinets of curiosities had existed as motley collections of unrelated fossils, plants, shells, coins, artifacts and fakes for many years by the time Dutch collector Levinus Vincent and his wife Joanna van Breda assembled their collection. But their cabinet was different. Historian Bert van de Roemer argues that Vincent intended to "emphasize the wonder of God's creations by restoring the natural world to its prelapsarian harmony." In other words, Adam and Eve's biblical fall basically broke nature, and Vincent and his wife intended to restore it through a meticulously arranged cabinet. (They weren't alone in thinking this way; some of the enthusiasm for inventions such as microscopes and telescopes stemmed from the belief that those tools would restore the superior senses humankind used to possess.) The wonder cabinet included some 600 vials of animal specimens preserved in alcohol. Besides living in an age when natural historians relied on the Bible to interpret the planet's history, they also believed that all of life's diversity could be assembled in a single collection. Other goodies in the collection included shells and insects artfully arranged in patterns resembling lace or embroidery. As Van de Roemer explains, this was no coincidence. Vincent wasn't just a collector but also a damask merchant and fabric designer.

Year: 1782Scientist: Robert de Paul de LamanonOriginally published in:Observations sur la PhysiqueNow appears in:Bursting the Limits of Time by Martin J.S. Rudwick
In the late 18th century, savants were beginning to realize that the earth had an ancient past, but it wasn't clear to everyone that the ancient past preceded humans. One savant who believed that humans had been around for a very long time was Lamanon. This illustration shows fossils reportedly found in the gypsum remains of an ancient lake near Paris. Two of the fossils look credible to modern eyes: the fossil tooth and the fossil fish. Lamanon characterized the tooth as that of a mammal that was likely extinct. The bird appears, in Rudwick's observation, "suspiciously well preserved." But more suspicious still is the key. The key's presence in this collection of fossils was based on the word of a quarryman who claimed to find the key 80 feet deep in the gypsum deposits. He produced not the key itself but a drawing of it in the sand. Since the quarryman seemed sensible, his account was believed. Lamanon wrote, "I therefore consider it certain not only that the existence of men preceded that of the present surface of the region around Paris, but also that the shores of this lake of selenitic waters were inhabited by men living together socially and that in their time the art of working mines and forging iron was already known. I know of several other facts analogous to this, which prove incontestably that the crafts were cultivated in the times that precede the great physical revolutions that have happened at the surface of the globe." Perhaps the sensible quarryman's account was so easily believed because it so easily fit with what some savants very much wanted to think.Larger image available

Year: 1664-1678Scientist/artist:Athanasius KircherOriginally published in:Mundus SubterraneusNow appears in:Athanasius Kircher's Theatre of the World by Joscelyn Godwin
German Jesuit Athanasius Kircher was a polymath who studied everything from magnetism to comparative religion. At a time when boundaries had not yet been drawn between science, religion and art, Kircher mingled these things to spectacular (if not entirely accurate) effect. During the 1660s and 1670s, he published two volumes of Mundus Subterraneus (The Subterranean World). The volumes covered gravity, the sun and moon, eclipses, volcanoes, ocean currents, weather, minerals, fossils, astrology, dragons, demons, alchemy, spontaneous generation and fireworks, among other topics. To explain the uncanny resemblances these stony images bore to birds, Kircher suggested a few possibilities, including chance, petrifaction, and divine disposition enacted by angelic and/or natural forces.Expanded image available

Year: 1664-1678Scientist/artist:Athanasius KircherOriginally published in:Mundus SubterraneusNow appears in:Athanasius Kircher's Theatre of the World by Joscelyn Godwin
Although the 17th-century scholar Kircher was often wrong about how fossils formed, he wasn't wrong every time. He provided a description that a modern scientist might accept when it came to these fossil fish. Kircher argued that when, say, a fish is encased in mud, a "lapidifying spirit" gradually turns the fish to stone. He further argued that the fish's internal organs and other soft tissues are consumed, or perhaps turned to dust. Although these fossil fish bear humanlike faces and more soft tissue than one could realistically expect from the fossilization process, Kircher's arguments about the process were cogent.Expanded image available

Year: 1664-1678Scientist/artist:Athanasius KircherOriginally published in:Mundus SubterraneusNow appears in:Athanasius Kircher's Theatre of the World by Joscelyn Godwin
Figured stones Kircher described in his Mundus Subterraneus also included quadrupeds (four-footed animals). Two examples appear here. The quadruped in the rock on the left looks like it has taken a beating (though the animal on the right looks a little too perfect). Although Kircher's figured stones may have been completely inorganic — with their figures enhanced by Kircher's imagination — the busted-up appearance of some of the quadrupeds in Kircher's figured stones aren't unlike the fragmented nature of some fossils, which may suffer anything from trampling to the crushing weight of rocks overhead to erosion.

Year: 1675Scientist/artist:Athanasius KircherOriginally published in:Arca NoëNow appears in:Athanasius Kircher's Theatre of the World by Joscelyn Godwin
In the late 17th century, Kircher produced a book on Noah's Ark for the 12-year-old king of Spain, Charles II. In this book, Kircher wrestled with problems that plagued other scholars and mapmakers of his time: how to reconcile religious orthodoxy with reality. According to Genesis, four rivers — Physon (or Pishon or Pison), Geon (or Gihon), Tigris and Euphrates — flowed out of Eden. Although the present-day paths of the Tigris and Euphrates were well known, tracking down the other two proved a tad problematic. Kircher also tried to square the biblical river routes with his conviction that all rivers originated in mountains. The origin of at least one river in this sumptuous illustration was conveniently concealed behind the text panel in the upper right. In between the rivers, Kircher's map showed snippets of Genesis stories, including the murder of Abel and a troublemaking snake. Adam and Eve lived inside an enclosed, rectangular, orderly garden.Larger image available

Year: 1675Scientist/artist:Athanasius KircherOriginally published in:Arca NoëNow appears in:Earth's Deep History by Martin J.S. Rudwick
In the book he wrote for Spain's preadolescent king Charles II, Kircher examined logistical problems of the flood and Noah's Ark, problems such as how the earth could have created and disposed of enough water to reach the highest mountaintops, and how Noah and his family dealt with the mountains of manure produced by their passenger pairs. Just as Kircher endeavored to explain certain aspects of the flood, he also used the flood to explain other things, such as the disappearance of a fabled landmass. In this map, the mottled areas indicate lands that remained permanently submerged after the biblical floodwaters retreated. Atlantis appears west of the Iberian Peninsula.Larger image available

Year: 1664-1678Scientist/artist:Athanasius KircherOriginally published in:Mundus SubterraneusNow appears in:Athanasius Kircher by Joscelyn Godwin, Rocks and Fossils by Busbey, Coenraads, Willis and Roots and A Source Book in Geology edited by Mather and Mason
The top image, shows Kircher's hypothesis that wind forces ocean water into underground reservoirs, from which it emerges through springs, rivers and lakes. Convinced that mountains gave rise to rivers, Kircher looked for the seminal mountains on each continent. The bottom image shows the earth's fiery core (which is also shown in the top image) feeding smaller fires that eventually emerge as volcanoes.

Year: 1664-1678Scientist/artist:Athanasius KircherOriginally published in:Mundus SubterraneusNow appears in:Possessing Nature by Paula Findlen
Though a little fanciful, this illustration of Mount Etna was far less speculative than Kircher's pictures on the earth's core. It was based on his own visit to the smoking volcano in 1637. The Jesuit visited Vesuvius, too, and wrote, "When I finally reached the crater, it was terrible to behold. The whole area was lit up by fires, and the glowing sulphur and bitumen produced an intolerable vapor. It was just like hell, only lacking the demons to complete the picture."Larger image available

Year: 1665Scientist/artist:Athanasius KircherOriginally published in:Mundus SubterraneusNow appears at: Athanasius Kircher at Stanford (http://www.stanford.edu/group/kircher/cgi-bin/site/)
Athanasius Kircher's Mundus Subterraneus covered subjects related to earth sciences when the processes of fossilization and crystallization were poorly understood. Kircher believed in a continual creative force in the universe, and to his mind, this creative force could devise objects with uncanny resemblances to living things. That might have been his explanation for this "toad stone."Larger image available

Year: 1648Scientist/artist:Ulisse AldrovandiOriginally published in:Musaeum MetallicumNow appears in: "Da Vinci's Paleodictyon: The Fractal Beauty of Traces" by Andrea Baucon in Acta Geologica Polonica
Mined from Jurassic limestone, Verona Stone was often used for ornamental purposes, and Ulisse Aldrovandi described it in his Musaeum Metallicum. Aldrovandi described the stone as a natural curiosity that imitated snakes. In fact, the odd shapes were probably caused by the activity of cephalopods, whose shells have been found in the same rock layer in abundance. The mollusks likely disturbed the sea floor, creating sinuous shapes. Although he misinterpreted Verona Stone, Aldrovandi did describe other trace fossils, such as bore holes, accurately.

Year: 1492Publisher: Sebastien BrandtOriginally published in: Open letterNow appears in:Meteorites by Alain Carion
In the late 15th century, meteorites were sometimes called thunderstones. More importantly, they were often taken as omens, sometimes mighty convenient ones. When a meteorite fell on the town of Ensisheim, Sebastien Brandt, a law professor at the University of Basel, interpreted the event as a message from God, namely that Maximilian of Austria should invade France. Whether or not it was the open letter that convinced him, Maximilian invaded. The fighting turned out well for Maximilian and he gained three provinces. Troops in tow, he visited Ensisheim and inspected the meteorite, suggesting the locals hang it in a local church. There the meteorite remained for centuries.Expanded image available

Year: 1825Scientist/artist:Henry De la BecheNow appears in: "The Geological Society and its Official Recognition, 1824-1828" by Patrick J. Boylan in Geological Society, London, Special Publications
This is not a goof. It's just to pretty to ignore. In the 1820s, London's Geological Society was on the hunt for recognition, including a Royal Charter of Incorporation, and rent-free digs for its meetings and collections. An early president of the society, William Buckland, secured those prizes, but something else eluded him. He wanted the society to have its own coat of arms, and the process was pretty formal, including "applying to the College of Heralds for a Grant of Arms," according to historian Boylan. Though Buckland failed to secure an official seal, he and fellow geologist Henry De la Beche tossed around ideas, including this charming sketch. (Buckland made his own coat-of-arms sketch, but it couldn't compare to De la Beche's.) An ichthyosaur and plesiosaur act as playful "heraldic supporters" for a shield, which itself bears a cross-section of a fossil-rich cave in the upper left, an ammonite trio in the upper right, and an idealized geological section of part of the Alps across the bottom. Above the shield is the traditional weapon-wielding arm, but instead of the customary knife, this one wields a geological hammer. The Geological Society did settle on a logo decades later. It was polished and professional, but far less interesting.

Year: 1776Originally published in:De Anima Brutorum CommentariaNow appears in: "In Retrospect: The Earliest Picture of Evolution?" by Fausto Barbagli in Nature, November 19, 2009 issue
Although many artists and scientists made mistakes, now preserved for posterity, plenty of other practitioners touched upon accurate ideas ahead of their time. Traditional wisdom maintains that the concept of evolution wasn't depicted prior to Lamarck's tree diagrams at the turn of the 19th century. But in the late 18th century, a Carmelite monk named Francesco Maria Soldini penned a book examining whether animals have souls. The Florentine publishers apparently decided to decorate the book with engravings bearing little relation to the text. The artists behind the engravings remain unknown, but this image apparently pictures animals moving from the sea to land. Perhaps inspired by the Neptunian notions popular at the time, the pictures could show early depictions of biological evolution, decades before Charles Darwin posed a workable theory.

Year: 1858Scientist/artist: Anna Maria RedfieldOriginally published in:Nature in Living FormsNow appears in:Aristotle's Ladder, Darwin's Tree by J. David Archibald
Born at the dawn of the 19th century, Anna Maria Redfield earned the equivalent of a master's degree from the first U.S. institution of higher learning devoted to female students: Ingham University, and became perhaps the first woman to design a tree-like diagram of animal life. Although tree-like, her diagram didn't show common ancestry but instead showed the "embranchements" established by Georges Cuvier: vertebrates, arthropods, mollusks, and "radiata" (today classified as cnidarian and echinoderm phyla). To be fair, this diagram was published before Darwin's Origin of Species but later editions of her work made no mention of evolution either. Instead, she wrote about our simian cousins, "The teeth, bones and muscles of the monkey decisively forbid the conclusion that he could by any ordinary natural process, ever be expanded into a Man." Still, her elegant work is great fun to behold even now.Larger image available

Year: 1870Scientists: John William Dawson, Alexander WinchellPublished in:Sketches of Creation by Alexander Winchell (Also discussed in Cradle of Life by J. William Schopf)
In the late 1850s, a local collector brought some rock samples to William Logan, head of the Geological Survey of Canada. In 1864, Logan showed the specimens to Dawson, who concluded that they were fossils of foraminifera. Unlike modern foraminifera, which are tiny, multi-chambered shells, these forams were huge. Perhaps, their extreme size resulted from their extreme age; these fossils came from rocks estimated to be over a billion years old. Dawson dubbed them Eozoön Canadense, or "dawn animal of Canada." Eozoön enjoyed the status of oldest known organism for years, and Winchell highlighted it in his book about the history of life. There was just one problem. In 1894, J.W. Gregory and Hugh Johnston-Lavis found eerily similar samples of big, old foraminifera in limestone blocks spat out quite recently by Mount Vesuvius. Magma intruding into layers of limestone can deform the limestone and create convincing pseudofossils.Larger image available

Year: 1565Scientist:Conrad GesnerOriginally published in:De Omni Rerum FossiliumNow appears in:The Birth and Development of the Geological Sciences by Frank Dawson Adams
Did you know rocks could have babies? Well maybe not, but that's just what a lot of people used to think. When some rocks were broken, they revealed smaller rocks inside, and some rocks were even rumored to spontaneously burst open, giving birth to little rocks. Where did people get these ideas? From rocks that are now called concretions. When layers of sediment cover an object and immediately harden, they form a tough nodule. (This often happens to fossils, and preserves them very well.) Sometimes, the inner layers of sediment in a concretion erode away, leaving the small core rattling around inside a tough outer layer. When the outer layer is broken open, it looks like the rock had a baby.

Year: 1598Scientist/artist: Jean BauhinOriginally published in: Treatise on German fountains at BollNow appears in:I Have Landed by Stephen Jay Gould
Today a fossil is identified as any evidence of ancient life. Centuries ago, fossils were identified as anything dug up from the ground, and savants frequently lumped items of organic and inorganic origins together. Here, Bauhin depicted a snail shell and a crystal together because they had the same general shape. Savants often looked for objects resembling body parts, hoping those "fossils" could cure the ailing organs.

Year: 1655Scientist/artist:Ole WormOriginally published in:Museum WormianumNow appears in:A History of Geology and Medicine edited by Moody, Duffin and Gardner-Thorpe
The medicine cabinets of Europe's upper crust often included glossopetrae, or serpent tongues. Until they were properly identified as fossil shark teeth, the objects were not just believed to be serpent tongues turned to stone, they were also prized for their alleged curative powers. Glossopetrae could speed childbirth, protect against snakebite, warn their owners of the proximity of poison by sweating in its presence, cure sore mouths, and even guard against diseases caused by witchcraft. In this illustration, the tooth in the upper left corner, with its two-pronged root, especially resembles a forked snake tongue.

Year: 1648Scientist/artist:Ulisse AldrovandiOriginally published in:Museum MetallicumNow appears in: "Questioning Thunderstones and Arrowheads" by Matthew R. Goodrum in Early Science and Medicine
As they sing on Sesame Street, one of these is not like the others. Although these items all have the same general shape, one of them clearly doesn't belong. In the early days of geology, many mistakes involved the misinterpretation of organic remains, but when nearly anything pulled out of the ground was called a fossil, and when naturalists based their interpretations largely on overall shape, they sometimes mingled fossils and human artifacts. In this picture, Aldrovandi mixed an arrowhead with shark teeth. Ceraunia ("thunderstones" now understood to be artifacts) were thought to form inside clouds, and fall to the earth when lightning struck. Glossopetrae ("tongue stones" now understood to be shark teeth) were sometimes rumored to fall from the sky during eclipses of the moon. As Conrad Gesner observed, some of his contemporaries confused thunderstones and tongue stones. In the course of the 17th century, naturalists figured out the origin of tongue stones. You might think that a flint arrowhead would be easier to figure out, but these Stone Age artifacts posed their own puzzle: Who would make an arrowhead out of rock when metal was far superior? After all, didn't the Bible say that God had imparted knowledge of metallurgy to Cain's descendant Tubal-Cain? In 1609, Boethius de Boodt proposed that ceraunia were metal tools that had turned to stone. Before that, Michele Mercati penned Metallotheca arguing that they were really stone artifacts. Mercati got around the metallurgy difficulty by suggesting that knowledge of metallurgy was temporarily lost in the aftermath of Noah's flood. His interpretation was closest to the truth regarding the artifacts' composition, if not their age, but his manuscript wasn't published until a century after his death in 1593. Modern science historians Glyn Daniel, Alain Schnapp and Matthew Goodrum have argued that encounters with New World peoples, and collection of their stone tools, helped savants like Mercati clear up the mystery surrounding Stone Age tools found in Europe.

Year: 1708Scientist: Carolus Nicolaus LangiusOriginally published in:Historia Lapidum Figuratorum HelvetiaeNow appears in:The Birth and Development of the Geological Sciences by Frank Dawson Adams
What 18th-century scholars regarded as "figured stones" are today recognized as fossils. The circular and star-shaped objects at the top appear to come from crinoid (sea lily) stems. The figure near the bottom of the frame is probably a trilobite fossil.Larger image available

Year: 1598Scientist/artist: Jean BauhinOriginally published in: Treatise on German fountains at BollNow appears in:I Have Landed by Stephen Jay Gould
In another example of the confusion over the organic versus inorganic origin of fossils, Bauhin drew what looked like stalactites dangling from the ceiling of a cave. In fact, these fossils belonged to belemnites — shells of squidlike animals.

Year: 1497Originally published in:Hortus SanitatisNow appears in:The Birth and Development of the Geological Sciences by Frank Dawson Adams
Even in the age of Pliny, savants recognized that some stones could attract iron, and further that some of these stones were bipolar, attracting iron on one side and repelling it on the other. Still, the power of these magnets (or lodestones, as they were called) was a tad overrated. Legends told of lodestone hills along the Indian coast so powerful that no ship held together by iron nails dared sail past. This picture shows the resulting tragedy as the nails fly to the hills and the passengers sink into the water.

Now appears in:Rocks and Fossils by Busbey, Coenraads, Willis and Roots
A commonly held belief during the Middle Ages and Renaissance was that lead could be turned to gold, as in this wishful depiction. Anti-alchemy laws forbidding transmutation of lesser metals into gold were not uncommon — not because the lawmakers thought transmutation would fail, but precisely because they thought it might succeed and undermine the economy. In his plan for the ideal alchemical factory, 17th-century polymath Johann Joachim Becher neatly divided up the tasks that different workers would do. Becher insisted that the laborers be illiterate, or at least denied access to pens and paper, and that laborers from different parts of the factory be forbidden to fraternize with each other and trade secrets. (In fact, 20th-century science does enable us to change lead to gold, but the energy requirements are so costly, it's easier to find gold the old-fashioned way.) Regardless of how alchemical gold might have changed commerce, debates raged about its usefulness in medicine; centuries ago, some people actually ingested gold in hopes of strengthening their hearts, but no one knew whether "alchemical" gold could have the same effect.

Year: 1652Scientist/artist:Elias AshmoleOriginally published in:Theatrum Chemicum BritannicumNow appears in:Alchemy: The Great Secret by Andrea Aromatico
Chemistry has a forerunner that is centuries older, less accurate and much less straightforward. The mysterious set of practices known as alchemy might all owe their origins, at least in part, to ancient writings attributed to Hermes Trismegistus. The writings in question probably date from the first two centuries AD, but Renaissance believers thought Hermes might be a contemporary of Moses (if not the great prophet himself) and the deliverer of divine knowledge to mankind. One of Hermes's great gifts was alchemy, the ability to transmute base metals into precious metals, but more importantly to attain spiritual insights embodied in the Philosopher's Stone. Medieval and Renaissance alchemists were expected to be two things at once: charitable and envious. They were to be charitable in sharing their knowledge with others for the betterment of the whole world. But they were also to be envious by safeguarding their esoteric wisdom from the vulgar masses who would misunderstand and possibly abuse it. As a result, alchemy books often communicated through the kind of symbolism that would be known as dog whistling today. The symbols included real and imaginary animals, monsters and heroes. This illustration, published in the 17th century, has been described as the bird of Hermes giving the alchemical dragon the celestial flux. And you thought your chemistry textbook was hard to decipher.Larger image available

Year: 1609Scientist/artist:Giambattista Della PortaOriginally published in:De DistillationeNow appears in:Alchemy: The Great Secret by Andrea Aromatico
Precursors of chemists lived in a world riddled with secrecy, symbolism and celestial correspondences. For instance, during the Middle Ages and Renaissance, copper wasn't just copper, it was the earthly material like the planet Venus. And gold corresponded to the sun, silver to the moon, Jupiter to tin, and Saturn to lead. Mercury was the name of both the planet and the shimmering liquid we now know is toxic. As silly as the mystical associations seem today, many alchemists did make discoveries about the metals they studied for spiritual enlightenment. They also built lab equipment. These images show a few alchemical vessels, a couple of them with their corresponding symbols. The savant writing about them, Della Porta, would have known about the expected stages of transmutation from pedestrian to spiritual metal in an alchemist's lab: black (Nigredo), white (Albedo), yellow (Citrinitas) and finally red (Rubedo). The Latin term Rubedo experienced a new popularity when it was appropriated in the 21st century by Tiffany jewelers for a very pretty pink alloy, but the jeweler apparently also appropriated alchemy's affinity for secrecy regarding the alloy's actual gold content.Larger image available

Year: c. 1700Originally appeared in:The Vessels of HermesNow appears in:The Vessels of Hermes — an Alchemical Album in Public Domain Review
Manly Palmer Hall was an early-20th-century mystic who published The Secret Teachings of All Ages in the 1920s, and acquired some remarkably weird manuscripts in the 1930s. One gem he purchased, perhaps at a Sotheby's auction, was an alchemical album by an unknown author, composed at the dawn of the 18th century. The watercolors in this album included symbolic illustrations hard to interpret today: cherubs representing salt, sulfur and mercury bearing a giant egg, and an androgynous creature created by alchemical processes. This illustration has been described as "the sublimation by the eagles after putrefaction." The sun and moon both smile upon a dragon that eats its own tail while perched on the belly of an upside down horse. A stack of eagles alights on the dragon, and the upturned horse apparently shoots flames from its hooves. Besides such handy tricks as turning base metal into gold, alchemy promised to enable its adherents to find the kind of esoteric wisdom hinted at in this manuscript. Skepticism about alchemy had thrived for centuries — Persian polymath Avicenna (ibn Sina) and Jesuit polymath Athanasius Kircher both doubted alchemical claims — but the ranks of the firm believers included such luminaries as Isaac Newton.Larger image available

Year: 1532Scientist/artist: Hieronymus BrunschwigOriginally published in:Liber de Arte DistillandiNow appears in:The Professor of Secrets by William Eamon
Although medieval and Renaissance alchemy often concerned itself with transmuting base metals into gold or achieving philosophical insights, other applications were considered more practical. This illustration shows alchemists in the process of distillation, a general process still in use today. These alchemists prepare distilled medicinal water. Though closer to the aims of modern chemistry than other facets of alchemy, some Renaissance distillation aims were a little overly ambitious. Though distillation, alchemists sought, in the words of science historian Bruce Moran, "a super-medicine, an elixir or aqua vitae that could purify physical bodies of their impurities, rid the human body of disease, and prolong life."Larger image available

Year: 1637Scientist/artist: Francesco StellutiOriginally published in:Trattato del Legno Fossile MineraleNow appears in:Fossil Woods and Other Geological Specimens by Andrew C. Scott and David Freedberg
"From what I have been able to see and observe, the wood is not generated from the seed or root of any plant whatsoever, but only from a type of earth, containing much clay, which is slowly transformed into wood," Stelluti wrote. Stelluti was wrong, and for members of the meticulous Lincean Academy, such errors were rare. The mistake is forgivable, though, considering the fossil wood in question had no fossil leaves attached, and had been carried far away from its original locality.

Year: 1676Scientist/artist:Robert PlotOriginally published in:The Natural History of OxfordshireNow appears in:The Dinosaur Papers edited by Weishampel and White
According to Robert Plot, every stone was designed by God for the edification or entertainment of humans, including this rock that looked like a funny face. Plot described this rock among other stones that looked like human eyes, human ears and human hearts.

Year: 1497Originally published in:Hortus SanitatisNow appears in:The Birth and Development of the Geological Sciences by Frank Dawson Adams
Just as humans can form "stones" in our gallbladders or kidneys, so can other animals. That much, medieval and Renaissance Europeans understood, though they seemed to think some stones came from different parts animals' bodies, such as the head of a frog. Here, a man extracts stones, called a bufonites, from the head of a frog who seems pretty good-natured about the whole process. Although you and I probably wouldn't want to handle these stony secretions (often called bezoar stones), they were once highly valued, some selling for 10 times their own weight in gold. Why? They were thought to be an antidote to all kinds of poison. In an age when the ranks of royalty were often dispatched with poison — sometimes by their own family members — antidotes were hot items.

Year: c. 1521Originally published in:Noble Lyfe and Natures of Man of Bestes Serpentys Fowles and FishesNow appears in: "Fossils as Drugs" by Christopher Duffin in Ferrantia
Although some animals do produce stony secretions, the stones reputed to come from frog heads were as rare as they were valuable. The text with this frog woodcut extolled the virtues of the toad stone: "Borax is a maner of tode that hathe a stone in his hede, & whan this stone is goten out the whyie that the tode dothe love than hathe the stone in hymselfe a fygure of an iye, but if it be taken out whan the tode is ded than hathe the venym taken awaye that iye and enpayred the stone. This tode whan that is stered or meued than swelleth it of his owne venym or poyson." Advice on procuring toad stones warned that such an object had to be extracted from a living frog by grabbing the rock after the frog somehow ejected it, but before the animal could "sup it up again." To coax the toads to do the desired casting out, the amphibians had to be placed on a piece of red cloth. (As simple as it sounds, requiring red material would have stopped plenty of toad stone seekers in their tracks; dyes that could color cloth a bright, reliable red were rare and expensive before the invention of synthetic dyes in the 19th century.) There was another reason that getting a rock out of a frog head would be pretty tough: The objects frequently identified as toad stones, or bufonites, were really fossil fish teeth, many from a species that lived during the Jurassic Period. Agostino Scilla, an early proponent of the modern definition of fossils — remains of ancient organisms — may have been the first person to correctly identify these objects.

Year: 1483Originally published in:Hortus SanitatisNow appears in: "Some Early Eighteenth Century Geological Material Medica" by Christopher J. Duffin in Geological Society, London, Special Publications
This woodcut shows the use of hematite in treating a nosebleed. The iron-rich ore was believed handy in treating the loss of blood from just about any human orifice. Considering iron figures into human blood as well as into hematite, perhaps the idea wasn't entirely misguided. And mere hematite was probably safer than some other wonder drugs of the time. Some concoctions involved bezoar stones — hardened concretions of undigested matter from the guts of various animals. When big, valuable bezoars were unavailable, savvy apothecaries developed pricey substitutes. Duffin recounts that one recipe mixed "small bezoars with comminuted precious stones (emerald, topaz, ruby, jacinth and sapphire), other geological materials (fossil shark's teeth, Terra Sigillata, stones from Cananor), semiprecious organic gems (pearl and coral), musk and ambergris, all bound together with hart's horn jelly. The hardened confections were covered with gold or silver leaf and given a high surface polish, emphasizing the high status and expensive nature of the bezoar substitute."

Year: 1565Scientist:Conrad GesnerOriginally published in:De Omni Rerum FossiliumNow appears in:The Birth and Development of the Geological Sciences by Frank Dawson Adams
For many years, Europeans had been finding weird stones, often pointy, often with holes in them. Today, these stones are understood to be ancient artifacts, namely axes with holes drilled in them for handles. Centuries ago, they were thought to be created by lightning strikes. These thunderstones were carried around or kept in houses to ward off damage from electrical storms.

Year: 1704Scientist: Michael Bernhard ValentiniOriginally published in:Natur und Minerialien KammerNow appears in: "Fossils as Drugs" by Christopher Duffin in Ferrantia
Fossils have a long history of being used as medicine by people who didn't know their medicines were millions of years old. One interpretation of belemnites was that they were Lyncurium or Lapis Lincis — lynx urine turned to stone. The 17th-century naturalist Anselm Boëtius de Boodt argued that belemnites were coveted Lyncurium, in part because when burnt, they stank like cat urine. Naturalists, apothecaries and chronically sick people all coveted these stinky stones because they were believed to cure a long list of ailments.

Year: 1749Scientist:Gottfried Wilhelm LeibnizOriginally published in:ProtogaeaNow appears in:Protogaea by Leibniz
Belemnites are the internal skeletons of extinct cephalopods, and these fossils flummoxed naturalists for centuries. To his credit, Leibniz argued that these strange stones were likely leftovers from once-living animals, though he wasn't sure which ones. He referred to them as "Fingers of Ida." Leibniz had more confidence in identifying fossil shark teeth, having been influenced by the polymath Steno. Although Leibniz scoffed at some contemporary notions about the curative abilities of shark teeth, he did advocate their use in cleaning human teeth.

Year: 1618Scientist/artist: Johannes KeplerOriginally published in:Epitome of Copernican AstronomyNow appears in: "Global Visions and the Establishment of Theories of the Earth" by Kerry Magruder in Centaurus, October 2006 issue
Although best known for his work in astronomy, Kepler also gave serious thought to the composition of the earth. He explained that the earth's axis was inclined thanks to magnetic fibers running parallel to it. He also compared the earth's daily motion to the spinning of a top. What perhaps seems stranger to the modern mind would be Kepler's conviction that the earth had a soul that both animated geological processes and responded to the positions of other planets.

Year: 1680-1689Scientist/artist: Thomas BurnetOriginally published in:Sacred Theory of the EarthNow appears in:Time's Arrow, Time's Cycle by Stephen Jay Gould
Most people today think of mountains as pretty if not beautiful, but Thomas Burnet argued that they were ugly — remnants of the humanity-punishing biblical flood. People didn't always listen to Burnet as they should have, so he emphasized his point with global maps showing asymmetrical mountain ranges. Before the Deluge, he was sure, the earth had been a perfect, aesthetically pleasing orb.Larger image available

Year: 1644Scientist/artist:René DescartesOriginally published in:Principia PhilosophiaeNow appears in: "Global Visions and the Establishment of Theories of the Earth" by Kerry Magruder in Centaurus, October 2006 issue
During Descartes's day, Europeans struggled to understand how the earth had developed mountains and sea beds. He proposed that, over time, the "outer shell" of an initially soggy earth had dried out, and the crust had collapsed in places. The idea influenced the work of Niels Stensen (Steno), who relied on the phenomenon to explain parts of earth's geology. Crustal collapse turned out to be wrong, but that didn't keep Steno from laying important foundations of modern geology, and it's not hard to see how crustal collapse would have provided a plausible explanation for many of earth's features.

Year: 1599Scientist: Giovanni Battista NazariOriginally published in:Della Tramutatione Metallica Sogni TreNow appears in:Astrology, Magic, and Alchemy in Art by Matilde Battistini, translated by Rosanna M. Giammanco Frongia
In producing this image, Nazari wasn't claiming that a creature like this really existed. But this "Philosophers' Mercury" image was intended to symbolize the near-magical metal. The way this three-headed, four-faced animal bit its own tail alluded to quicksilver's dual nature, both solid and volatile.